1. Field of the Invention
The invention relates to an electrical connector, and more particularly to a sharable socket structure.
2. Related Art
The universal serial bus (USB) is the most popular interface which satisfies the signal transmission specification in the computer. The connector socket and the transmission cable satisfying this specification can connect the computer to the peripheral apparatus, such as a mouse or a keyboard, and can immediately work to achieve the plug-and-play function.
In order to satisfy the requirement of the high flow data transmission, another transmission specification, such as external serial ATA (eSATA), satisfying the plug-and-play function is also proposed, wherein the transmission amount of this specification is higher than that of USB.
The interface of USB is not compatible with that of eSATA. So, these two similar sockets cannot be shared.
Referring to FIG. 1, a conventional signal line connector includes a plastic base 10, four first terminals 20, seven second terminals 25 and a metal casing 30.
The plastic base 10 has a USB connector socket 11 and an eSATA connector socket 15. A tongue 12 is disposed in the USB connector socket 11, and a tongue 16 is disposed in the eSATA connector socket 15.
The first terminal 20 is fixed to the plastic base 10 and has a pin 22 and a contact 21, which can elastically move up and down. The contact 21 is disposed in the USB connector socket 11 and protrudes downwardly from the tongue 12. The pin 22 extends downwardly from the plastic base 10 and is thus connected to a circuit board 35.
The second terminal 25 is mounted on the plastic base 10 and has a pin 27 and a contact 26, which cannot elastically move. The contact 26 is disposed in the eSATA connector socket 15 and protrudes upwardly from the tongue 16. The pin 22 extends downwardly from the plastic base 10 and is thus connected to the circuit board 35.
The metal casing 30 covers peripheral surfaces and a top surface of the plastic base. One surface of the metal casing 30 is formed with openings 31 and 32 for exposing the USB connector socket 11 and the eSATA connector socket 15.
As shown in FIG. 2, a rectangular USB connector 40 satisfying the USB 2.0 specification has a plastic body 41, an external iron casing 42 and four terminal connection points 43. The external iron casing 42 is formed with a chamber 44 after covering the plastic body 41. The hatched region represents the plastic body 41, and the four terminal connection points 43 have no elasticity and are exposed to the chamber 44. As shown in FIG. 1, the chamber 44 of the USB 2.0 connector 40 corresponds to the tongue 12 of the USB connector socket 11 to be inserted for electrical connection. At this time, its terminal connection points 43 are in elastic contact with the contacts 21 of the first terminal 20.
As shown in FIG. 3, an eSATA connector 45 substantially has a rectangular shape and has two slightly protruding sides. The eSATA connector 45 has a plastic body 46, an external iron casing 47 and four terminal connection points 48. The middle of the plastic body 46 is formed with a chamber 49, wherein the hatched region represents the plastic body 46. The seven terminal connection points 48 have the elasticity of up and down movement and are exposed to the chamber 49. As shown in FIG. 1, the chamber 49 of the eSATA connector 45 corresponds to the tongue 16 of the eSATA connector socket 15 to be inserted for electrical connection. At this time, its terminal connection points 48 are in elastic contact with the contacts 26 of the second terminal 25.
The USB connector socket 11 disposed on the conventional signal line connector is only suitable for the inserted USB connector, while the eSATA connector socket 15 is only suitable for the inserted eSATA connector. That is, the socket cannot be shared by the USB and eSATA connectors. However, the functional requirements of the computer are gradually increased. According to different requirements of the users, the computer may need to be connected to four signal lines with the USB connectors but need not to be connected to the signal line with the eSATA connector. Alternatively, the computer may need not to be connected to the signal line with the USB connector but need to be connected to four signal lines with the eSATA connectors. Thus, the computer has to be provided with four USB connector sockets and four eSATA connector sockets in order to satisfy various requirements of the users. Therefore, the sockets occupy more space in the chamber and the cost is increased.
In order to facilitate the usage, the shareable socket with the signal line of the USB connector and the signal line of the eSATA connector has been proposed. However, the connection points of the USB connector partially overlap with the connection points of the eSATA connector on the X coordinates of the sequentially arranging direction of the terminals. So, the currently designed shareable sockets are classified into the following two kinds.
In the first kind, four first terminals connected to the connection points of the USB connector and seven second terminals connected to the connection points of the eSATA connector are respectively disposed on two surfaces of the tongue. However, the thickness of the tongue is so thin that the space for the elastic movement of the first terminal is very small.
In the second kind, four first terminals connected to the connection points of the USB connector and seven second terminals connected to the connection points of the eSATA connector are disposed on the same surface of the tongue. The four first terminals have to be disposed in the gaps between the seven second terminals. So, when the USB connector is connected thereto, the connection points of the USB connector cannot be precisely aligned with and connected to the first terminals. Thus, the electrical connection reliability is very small.
Furthermore, in order to shorten the transmission time, the current USB connector has been developed to the specification of USB 3.0. The connection interface of the USB 3.0 connector has an additional row of terminals as compared with the USB 2.0 connector. So, the transmission speed becomes higher. Thus, if the USB 3.0 connector and the eSATA connector have to be integrated, then three rows of terminals have to be provided in the shareable socket, and the difficulty in manufacturing may be increased.